/*
*  linux/kernel/traps.c
*
*  (C) 1991  Linus Torvalds
*/

/*
* 'Traps.c' handles hardware traps and faults after we have saved some
* state in 'asm.s'. Currently mostly a debugging-aid, will be extended
* to mainly kill the offending process (probably by giving it a signal,
* but possibly by killing it outright if necessary).
*/
#include <string.h>

#include <linux\head.h>
#include <linux\sched.h>
#include <linux\kernel.h>
#include <asm\system.h>
#include <asm\segment.h>
#include <asm\io.h>

static __inline char get_seg_byte(unsigned short _seg, char *addr)
{
	register char __res;

	__asm mov	ax, _seg
	__asm push	fs
	__asm mov	fs, ax
	__asm mov	eax, addr
	__asm mov	al, fs :[eax];
	__asm pop	fs
	__asm mov	__res, al

	return __res;
}

static __inline unsigned long get_seg_long(unsigned short _seg, long *addr)
{
	register unsigned long __res;

	__asm mov	ax, _seg
	__asm push	fs
	__asm mov	fs, ax
	__asm mov	eax, addr
	__asm mov	eax, fs:[eax];
	__asm pop	fs
	__asm mov	__res, eax

	return __res;
}

static __inline unsigned short _fs()
{
	register unsigned short __res;

	__asm mov	ax, fs
	__asm mov	__res, ax

	return __res;
}

int do_exit(long code);

void page_exception(void);

void divide_error(void);
void debug(void);
void nmi(void);
void int3(void);
void overflow(void);
void bounds(void);
void invalid_op(void);
void device_not_available(void);
void double_fault(void);
void coprocessor_segment_overrun(void);
void invalid_TSS(void);
void segment_not_present(void);
void stack_segment(void);
void general_protection(void);
void page_fault(void);
void coprocessor_error(void);
void reserved(void);
void parallel_interrupt(void);
void irq13(void);

static void die(char * str, long esp_ptr, long nr)
{
	long * esp = (long *)esp_ptr;
	int i;

	printk("%s: %04x\n\r", str, nr & 0xffff);
	printk("EIP:\t%04x:%p\nEFLAGS:\t%p\nESP:\t%04x:%p\n",
		esp[1], esp[0], esp[2], esp[4], esp[3]);
	printk("fs: %04x\n", _fs());
	printk("base: %p, limit: %p\n", get_base(current->ldt[1]), get_limit(0x17));
	if (esp[4] == 0x17) {
		printk("Stack: ");
		for (i = 0; i < 4; i++)
			printk("%p ", get_seg_long(0x17, i + (long *)esp[3]));
		printk("\n");
	}
	str(i);
	printk("Pid: %d, process nr: %d\n\r", current->pid, 0xffff & i);
	for (i = 0; i < 10; i++)
		printk("%02x ", 0xff & get_seg_byte((unsigned short)esp[1], (i + (char *)esp[0])));
	printk("\n\r");
	do_exit(11);		/* play segment exception */
}

void do_double_fault(long esp, long error_code)
{
	die("double fault", esp, error_code);
}

void do_general_protection(long esp, long error_code)
{
	die("general protection", esp, error_code);
}

void do_divide_error(long esp, long error_code)
{
	die("divide error", esp, error_code);
}

void do_int3(long * esp, long error_code,
	long fs, long es, long ds,
	long ebp, long esi, long edi,
	long edx, long ecx, long ebx, long eax)
{
	int tr;

	__asm xor	eax, eax
	__asm str	ax
	__asm mov	tr, eax
	printk("eax\t\tebx\t\tecx\t\tedx\n\r%8x\t%8x\t%8x\t%8x\n\r",
		eax, ebx, ecx, edx);
	printk("esi\t\tedi\t\tebp\t\tesp\n\r%8x\t%8x\t%8x\t%8x\n\r",
		esi, edi, ebp, (long)esp);
	printk("\n\rds\tes\tfs\ttr\n\r%4x\t%4x\t%4x\t%4x\n\r",
		ds, es, fs, tr);
	printk("EIP: %8x   CS: %4x  EFLAGS: %8x\n\r", esp[0], esp[1], esp[2]);
}

void do_nmi(long esp, long error_code)
{
	die("nmi", esp, error_code);
}

void do_debug(long esp, long error_code)
{
	die("debug", esp, error_code);
}

void do_overflow(long esp, long error_code)
{
	die("overflow", esp, error_code);
}

void do_bounds(long esp, long error_code)
{
	die("bounds", esp, error_code);
}

void do_invalid_op(long esp, long error_code)
{
	die("invalid operand", esp, error_code);
}

void do_device_not_available(long esp, long error_code)
{
	die("device not available", esp, error_code);
}

void do_coprocessor_segment_overrun(long esp, long error_code)
{
	die("coprocessor segment overrun", esp, error_code);
}

void do_invalid_TSS(long esp, long error_code)
{
	die("invalid TSS", esp, error_code);
}

void do_segment_not_present(long esp, long error_code)
{
	die("segment not present", esp, error_code);
}

void do_stack_segment(long esp, long error_code)
{
	die("stack segment", esp, error_code);
}

void do_coprocessor_error(long esp, long error_code)
{
	if (last_task_used_math != current)
		return;
	die("coprocessor error", esp, error_code);
}

void do_reserved(long esp, long error_code)
{
	die("reserved (15,17-47) error", esp, error_code);
}

void trap_init(void)
{
	int i;

	set_trap_gate(0, &divide_error);
	set_trap_gate(1, &debug);
	set_trap_gate(2, &nmi);
	set_system_gate(3, &int3);	/* int3-5 can be called from all */
	set_system_gate(4, &overflow);
	set_system_gate(5, &bounds);
	set_trap_gate(6, &invalid_op);
	set_trap_gate(7, &device_not_available);
	set_trap_gate(8, &double_fault);
	set_trap_gate(9, &coprocessor_segment_overrun);
	set_trap_gate(10, &invalid_TSS);
	set_trap_gate(11, &segment_not_present);
	set_trap_gate(12, &stack_segment);
	set_trap_gate(13, &general_protection);
	set_trap_gate(14, &page_fault);
	set_trap_gate(15, &reserved);
	set_trap_gate(16, &coprocessor_error);
	for (i = 17; i < 48; i++)
		set_trap_gate(i, &reserved);
	set_trap_gate(45, &irq13);
	outb_p(inb_p(0x21) & 0xfb, 0x21);
	outb(inb_p(0xA1) & 0xdf, 0xA1);
	set_trap_gate(39, &parallel_interrupt);
}
